Teflon Coated Fiberglass

General Composites Discussions Composites Talk
#1

I am using a 100gsm spread tow carbon fiber to create airfoils. The laminate is very thin with only two layers. I have tried two different types of peel plies from Airtech. One was a standard peel ply and the other was superlease blue which is a silicon coated peel ply. The problem is since its such a thin piece when pulling the peel ply out it distorts the very sensitive shape of the airfoil.

Does anyone have any experience using teflon coated fiberglass? How does it compare to a silicon coated peel ply.

thanks

#2

I have used teflon coated fibreglass (with and without the sticky backed adhesive face). It works well for me.

The only points I can think to add is that it will only do clean shapes and will not form to fit over a compound curve. Also in comparioson to peel plies it will not pull any resin out of the laminate so that may be of importance with very light skins?

#3

Luckily it is a 2d curve extruded so complex curves are not an issue. How much effort does it take to pull the teflon coated fiberglass out? I use a teflon sheet to keep the carbon from sticking to the mold and it peels off like a non stick film. Very easy. I am hoping that is how the teflon coated fiberglass will act also. All of the damage so far is coming from the removal of peel ply.

#4

It removes easily like a non stick surface.

#5

What’s the difference between a Teflon coated fibreglass and something like a PTFE release film? I mean I know the differences between the materials, but peel ply is always very difficult to remove, why would you not just use PTFE (perf or non-perf) instead?

#6

I also ordered some ptfe release film. I honestly dont know the difference.

#7

Teflon coated fibreglass is a heavier and reinforced material that stays flatter than a plastic release film. It’s also very durable and good for 100s of releases if it is looked after.

It seems to bag down really nice, even, flat and firm and it pulls no resin from the job like non perf film.

The sticky back stuff is great for a quick mould surface. Build a mould from whatever material you have and make it smooth, then wrap with the sticky back fibreglass PTFE. Ready to go, even for ovens and pre preg if the mould material is suitable.

#8

Doesn’t sound like a bad material then! Where are you getting it from in Perth Fasta, I’d be quite interested in trying it out.

#9

I buy it from Lavender in Qld. No stock that I know of in Perth.

#10

I expected as much, but that’s ok, I buy my vac bag from Lavender so I’ll give some a shot next time.

#11

Ok did an infusion last night with the teflon coated fiberglass. I will be pulling it tonight. I will let you know how it goes. Sadly the part will probably not come out great as it was late and at the end when I was clamping the exit line I spilled the reservoir cup and it took air. It was in green stage so hopefully it might be okay but I doubt it. I will at least still be able to see if the teflon coated fiberglass sticks though.

#12

The teflon coated fiberglass was better than peel ply but marginaly. The problem is the very fine porosity of the material allowed for many small epoxy connections. Going to try again but with a coated perforated release film this time.

#13

I would recommend trying a PTFE release film, you can get it in a perforated version. If you don’t use a spray adhesive to hold it down when dry stacking then you should find it releases extremely easily. If you use a spray adhesive then I find that tends to make it a lot harder to remove.

What I like to do as well when I’ve got parts that I know are a bit flimsy and probably not even as stiff as the flow mesh full of resin; I put a strip of peel ply or tape or something in between the flow mesh and the release film along one edge of the part on the flange (so not on the part at all. This then allows you to lift up and get underneath the flow mesh and pull it off the release film, which is often easier than trying to remove both at once. If it’s still a bit difficult, try sliding a plastic knife under the infusion mesh before you try to pull it off.

#14

I am just coming back to ask about pulling the peel ply and the distorting part. Wouldn’t the cured part just spring back to the correct shape anyway? I assume this is a part already out of the mould?

I use a cheap polyester peel ply (called polysheen) that is typically used as something you would find in a jacket lining. It releases easier than many of the true “peel plies” and only $2 pm. It’s lighter and finer than any other peel peel I have seen.

#15

Pulled the wing out this morning and the ETFE mp25 release film from Airtech is definitely the way to go. The only issue I had was a few dry spots. Possibly might need larger pores, clamp the resin feed line to reduce the speed, or de gas the epoxy better.

#16

Yeh throttling the flow back a touch should fix that.

#17

Quick note on sourcing Teflon coated fiberglass in the states and Europe. Taconic industries is a producer and will sell direct (at least in the states,I haven’t tried in Europe) They supply airtec with what they rebrand as Tooltec. Buying direct is about 40% cheaper vs Airtec. I’ve only bought full tools (36 yards) but I believe they will sell cut yardage but there will probably be a minimum

#18

Would using a red flow media help relieve this issue versus a green flow media?

#19

I haven’t tried to be honest, I buy 105m rolls of the green stuff so I’ve never bothered to try another type!

If you throttle the flow to about an inch per minute, I find that sorts out any dry spot issues.

#20

Would adding peel ply on top of the release film help saturate the carbon better also?
Thanks for all of the help!